1. Field of the Invention
The present invention relates to an ink cartridge comprising a pivotable member positioned in an ink chamber.
2. Description of Related Art
A known image recording apparatus, as described in Patent Application Publication No. JP-A-2009-132098, adopts a tube-supply system, in which an ink cartridge is positioned outside a carriage carrying a recording head, and the ink cartridge and the recording head are fluidically connected to each other via a flexible tube. The ink cartridge is configured to be mounted to a cartridge mounting portion in a horizontal direction via an opening formed at the front of the recording apparatus. The cartridge mounting portion is configured to removably receive the ink cartridge therein. When the ink cartridge is mounted to the cartridge mounting portion, a path through which ink flows is formed between the ink cartridge and the recording head. Ink is supplied from the ink cartridge to the recording head via the path.
Another known image recording apparatus, as described in Patent Application Publication No. JP-A-2007-15393, has an ink cartridge having an detection portion and a cartridge mounting portion having a sensor configured to detect the detection portion for an amount of ink stored in the ink cartridge to be determined by the image recording apparatus. For example, the ink cartridge has a pivotable member positioned in an ink chamber of the ink cartridge, and the pivotable member is configured to move based on an amount of ink stored in the ink chamber. The pivotable member has the detection portion positioned in a detection chamber which is in fluid communication with the ink chamber. By the detecting the position of the detection portion, it is possible to determine whether the ink amount in the ink chamber becomes less than a predetermined amount.
During mounting of the above-described cartridge to the cartridge mounting portion, acceleration in the direction of mounting is applied to the ink cartridge and/or the ink cartridge moves up and down due to a clearance between the ink cartridge and the cartridge mounting portion. That may cause bubbles to be formed in the ink chamber and/or a film of ink may be formed between the detection portion and a wall surface of the detection chamber surrounding the detection portion. The bubbles and/or the film of ink may hinder the movement of the pivotable member and the pivotable member may not move even when the ink amount in the ink chamber becomes less than the predetermined amount. In such a case, it is wrongly determined that the ink amount is still greater than or equal to the predetermined amount although the actual ink amount is less than the predetermined amount.